It is known in the art to use retractors and/or cannulas to provide a surgeon with an access portal to a surgical site in a patient's body. In particular, retractors and/or cannulas may be used to perform spinal operations, for example, discectomies, laminectomies, facectomies, pedicle screw fixation, etc., such as in minimally invasive procedures.
Known minimally invasive fixation systems have certain drawbacks. For example, retractors generally cause more trauma to the body than expandable cannulas since retractors tend to stretch tissue from the skin down to the surgical site.
While using cannulas (i.e., expandable cannulas, fixed diameter cannulas, etc.) may reduce trauma to the body as compared to retractors, for many surgical procedures, a surgeon must use a number of cannulas positioned adjacent to one another. A major drawback of using multiple cannulas is that if the surgeon needs to reposition adjacent cannulas, the cannulas may interfere with one another.
Thus, it is desirable to have a minimally invasive fixation system which provides a surgeon with increased ability to move and manipulate surgical instrumentation and implants into and within the body as well as an increased ability to visualize a surgical site while, at the same time, causing reduced amounts of trauma to the body. It is also desirable to provide a system which may be used to guide instrumentation into the body and may be configured so that parts of the system do not interfere with each other.